SOURCES: U.S. Department of Transportation,
Research and Innovative Technology Administration, Bureau of Transportation
Statistics, based on data from Department of Commerce, Bureau of Economic
Analysis, National Economic Accounts, National Incomes and Products Account, www.bea.gov/national/, as of Sept. 16, 2010. TEU data based on data from U.S.
Department of Transportation, Maritime Administration, which are drawn from The Journal of Commerce, Port Import Export Reporting Service (PIERS).